1. Field of the Disclosure
Exemplary aspects of the present disclosure relate to an apparatus for detecting surge voltage and a method thereof, and more particularly, to an apparatus for detecting surge voltage configured to efficiently perform a trouble shooting of parts and maintenance/repair of a system by detecting a surge voltage using a shunt regulator, and a method using the apparatus.
2. Description of Related Art
A variety of methods across an entire industrial field are used to protect various products from surge voltages. To be more specific, a PLC (Programmable Logic Controller) provides various functions of such as, but not limited to, digital input/output, analog input/output, communications, position determining and high speed counter. The digital input/output is one of the most frequently used functions among the variety of functions. Hence, the digital input/output takes the highest rate in field claims, and particularly, parts damage is most frequently generated due to surge voltages inputted to a DC output terminal.
FIG. 1 is a schematic circuit configuration of a DC output module in a PLC according to prior art.
Referring to FIG. 1, the DC output module transmits an MPU (Micro Processing Unit) output signal to an output driving transistor (TR) using a photo coupler (PC1) and facilitates a stable output by limiting a surge voltage through a zener diode (ZD). A DC output is turned on or off according to a program prepared by a PADT (Programming and Debugging Tool), and a load, which is an external device used by a user, is connected to a power source (15) of a predetermined voltage (e.g., 24V).
The photo coupler (PC1) is driven when a DC output is applied through an MPU (Micro Processing Unit), whereby an output signal of the photo transistor is transmitted to the output driving transistor (TR). As a result, the output driving transistor (TR) is turned on to realize an output operation, in which a current flows from the power source (15) along the load (14). At this time, a zener diode (ZD) was conventionally used to limit a surge voltage. However, parts are frequently damaged to result in a product defect, when a surge voltage (e.g., 40V) is applied for a long time that exceeds a maximum voltage (e.g., 38.7V) limitable by the zener diode (ZD).